Tapco Lower Parts Kit AR-15 Platform Black. The pieces in the TAPCO Lower Parts Kit are highly wear-resistant and are able to withstand the wear and tear of continuous shooting. Many of the parts in the TAPCO Lower Parts kit feature a black phosphate finish that provides corrosion protection from extended shooting. Includes: Takedown/Pivot Pin Detents (2) Bolt Catch Spring (1) Safety Detent Pin (1) Bolt Catch Plunger (1) Bolt Catch Roll Pin (1) Buffer Retention Pin (1) Trigger Pins 5.56 (2) Safety Detent Spring (1) Spring for Buffer Retainer 5.56 (1) Springs for Takedown/Pivot Detents 5.56 (2) Spring for Mag Catch (1) Bolt Catch (1) Safety Selector 5.56 (1) Magazine Catch Button 5.56 (1) Magazine Catch 5.56 (1) Pin for Receiver Pivot 5.56 (1) Pin for Receiver Takedown 5.56 (1) Specifications for Tapco TAP22037 Lower Parts Kit AR-15 Platform Black: Manufacturer: Tapco Color: Black Finish: Phosphate Fabric/Material: Steel Gun Make: AR Platform Gun Model: AR-15 Tapco TAP22037 Lower Parts Kit AR-15 Platform Black